Linear alpha-olefins are widely used commercially as important materials used for comonomers, detergents, lubricants, plasticizers, etc., and in particular, 1-hexene and 1-octene are widely used as comonomers for controlling the density of polyethylene during the preparation of linear low-density polyethylene (LLDPE).
In addition, since alpha-olefins have various different application fields or market sizes according to the kind, a technology of selectively producing a specific olefin is commercially very important, and recently, many studies have progressed on chromium catalyst technology for preparing 1-hexene or 1-octene with high selectivity through selective ethylene oligomerization.
Specifically, U.S. Pat. No. 7,361,623 discloses a catalyst system for the production of 1-hexene and 1-octene using chromium as a central metal, but this catalyst system does not consistently maintain the reaction activity depending on the reaction time, and the reaction rate tends to greatly decrease.
In addition, Korean Patent No. 10-0435513 discloses a catalyst system for the production of 1-hexene using chromium as a central metal, but this catalyst system exhibits performance of the catalyst under the conditions of high temperature and high pressure, and thus there is a limit in terms of energy consumption with this type of catalyst.
Accordingly, there has been a continuing demand for multimerization reaction activity and high selectivity which are consistently maintained during the reaction when preparing alpha-olefins such as 1-octene or 1-hexene.